Free-Standing, Interwoven Tubular Graphene Mesh-Supported Binary AuPt Nanocatalysts: An Innovative and High-Performance Anode Methanol Oxidation Catalyst

The Efficiency Study of Graphene Synthesis on Copper Substrate via Chemical Vapor Deposition Method with Methanol Precursor

Few-layer graphene was successfully synthesized on copper foil via chemical vapor deposition with methanol as a carbon source. This was confirmed by optical microscopy observation, Raman spectra measurement, I_2D/I_G ratio calculation, and 2D-FWHM value comparisons. Monolayer graphene was also found in similar standard procedures, but it required higher growth temperature and longer time periods. The cost-efficient growth conditions for few-layer graphene are thoroughly discussed via TEM observation and AFM measurement. In addition, it has been confirmed that the growth period can be shortened by increasing growth temperature. With the H₂ gas flow rate fixed at 15 sccm, few-layer graphene was synthesized at the lower growth temperature of 700 °C in 30 min, and at 900 °C growth temperature in only 5 min. Successful growth was also achieved without adding hydrogen gas flow; this is probably because H₂ can be induced from the decomposition of methanol. Through further defects study of few-layer graphene via TEM observation and AFM measurement, we tried to find possible ways for efficiency and quality management in graphene synthesis in industrial applications. Lastly, we investigated graphene formation after pre-treatment with different gas compositions, and found that gas selection is a crucial factor for a successful synthesis.

One-Pot Synthesis of Pt Nanobowls Assembled from Ultrafine Nanoparticles for Methanol Oxidation Reaction

Simultaneously engineering a bowl-like and ultrafine nano-size structure offers an attractive route to not only increase the utilization efficiency of noble metals, the specific surface areas and the availability of active sites, but also boost the structural robustness and long-term stability. However, a great challenge remains in terms of the methods of synthesis. Herein, we report a facile one-pot hydrothermal method for the preparation of hollow porous Pt nanobowls (NBs) assembled from ultrafine particles. N,N'-methylenebisacrylamide (MBAA) acts as a structure-directing agent that forms a self-template with Pt ions and drives the nucleation and assembly of Pt metals, resulting in the fabrication of Pt NBs from ultrafine particles. By virtue of their unique structure and morphology, the optimized Pt NBs exhibited enhanced electrocatalytic methanol oxidation reaction (MOR) activity with 3.1-fold greater mass activity and 2.6-fold greater specific activities compared with those of commercial Pt black catalysts, as well as excellent stability and anti-poisoning ability.